Increase Aerobic Capacity
Whether the athlete has just completed their off-season, or if they have been reintroduced to training with a more structured Preparation phase - for all THP athletes, training begins in earnest during the 4-8 week Foundation phase. During this phase, they will begin laying the foundations of their Aerobic Capacity (VO2max).
Once again, the precise nature of this phase will depend upon the individual circumstances, and in particular, the intensity level of the specific event being trained for. For example, if the event being trained for is taking place in the easy or moderate intensity domains (Levels 2-4), provided the athlete is well adapted to high intensity interval training - the primary intensity focus of the Foundation phase will be on higher intensities (Levels 5 and 6).
In this instance, although training volume will certainly be increasing, to accommodate the high intensity, we won’t be seeking a peak in volume at this phase of training. Development of the Aerobic Capacity will instead be achieved, through a combination of moderately high training volume, and high intensities.
Conversely, if the target event will be taking place in the high intensity domains (or if the athlete is not well adapted to high intensity interval training), the primary workout focus will be on more moderate intensities. In this instance, we will be looking to maximise aerobic capacity by maximising training volume - rather than relying primarily on training intensity.
The rational behind always training the least specific intensity levels first, is so that the race specific intensity levels can be focused on closest to the time of event. This is the most fundamental principal of periodisation. The closer to an event you get - the more specific your training needs to become.
Where an athlete competing in easy to moderate intensities, is not well adapted to training at high intensities so early in a training cycle. They have no option but to train in a linear (or classically) periodised way - with high intensity being performed closer to the event when they are more physically prepared. This doesn’t mean that their training won’t become more specific as they approach race day - it simply means that they limit the amount of high intensity they perform during the Foundation phase.